The atomic force microscope (AFM) scanning head based on the qPlus technology is preliminarily designed and assembled. The silicon cantilever sensor is replaced by quartz tuning fork type force sensor. Preamplifier circuit is designed and frequency characteristic of this scanning head is also analyzed. Finally, the experimental device for this scanning head is set up to make performance test. The test results show that the scanning head has a high sensitivity in the mode of frequency modulation. Meanwhile, the analysis of frequency characteristic indicates that the weight of tip and the bonding portion is the main factor to influence the resonant frequency of this scanning head. This research provides experiences for the design and assembly of this type scanning head and also lays a foundation for further study.

Aiming at the low accuracy in localization and sensitivity to noise in traditional edge detection algorithm, an algorithm of sub-pixel edge detection based on Gauss integral curve fitting is proposed. The gray value of discrete points on pixel edge normal section line is calculated with surface interpolation, and fitting Gauss integral curve, achieving accurate location of sub-pixel edge by searching the mean point of Gauss integral curve. Experiment with the gauge block line edge, and comparing with the existed sub-pixel edge detection algorithm, the experiment show that algorithm of sub-pixel edge detection based on Gauss integral curve fitting has high location accuracy, and can reach 1 μm, it also has high reliability and speed, and can be used for high precision measurement.

In order to solve the traceability problem that the laser particle counter can not be implemented by condensation nucleus counter based on direct comparing method, according to the principle of Bernoulli gas flow and the calculation method of aerosol dilution ratio, the dilution process of aerosol is analysed. As the increase of added gas flow,it has a problem that the pressure inside the dilution chamber is not constant. A new method of aerosol dilution to meet the traceability issues of laser particle counter is proposed. The results show that the new method could settle the interference matter of aerosol outlet flow caused by make-up gas, and keep a better uniformity among 0~90 times particles dilution ratio of different diameter in high concentration of aerosol. The max relative error of the measured data and the theoretical calculation is no more than 4.4%.

The model of cylindrical blackbody cavity is established, based on the integral equation method,finite element analysis method, Monte-Carlo method , the effective emissivity of blackbody cavity is calculated, and comparison and analysis the different cavity geometry, cavity material emissivity , the probe distance from mouth cavity and other factors have impact on the effective emissivity of the blackbody cavity. The results show that under the same cavity length to diameter ratio, the aperture ratio, material emissivity and other conditions, namely the length to diameter is larger, the aperture ratio smaller, the cavity material emissivity larger then the blackbody cavity have larger effective emissivity.

To eliminate the Abbe error in large length laser measurement, an algorithm which based on three independent laser interferometers is proposed. The mounting positions of three interferometers can be arranged in any triangle. By using the length data measured from the three interferometers, and with the geometric relationship between the mounting positions of the instrument to be calibrated and the three interferometers, a virtual interferometer which has a common path with the calibrated instrument is constructed, then the length measuring formula is derived. This method has no special requirement respect to the mounting positions of the three interferometers, so it is very easy to implement in practice. To verify the effectiveness of the algorithm, relying on the indoor 80 meters large length standard measurement device, by changing the mounting position of the calibrated instrument, 3 different experiments are carried out within 45 m measurement range. As the experiment indicates that after eliminating the Abbe error, the maximum of the other remaining error is only 1.10 μm, the result show that the proposed algorithm can eliminate the Abbe error effectively.

Urbanization has concentrated over 50% of the global population and more than 70% of the carbon emissions. Uncertainties in carbon emissions are very large or unknown at the spatial scale of individual cities, and 50% to 100% errors are not uncommon. The temporal and spatial distribution of greenhouse gas concentration is introduced, and the basic idea of carbon emission inversion model is described. Current NIST funded studies in several cities using top-down approach to estimate carbon emissions. Based on measurement of greenhouse gas concentration and accurate dispersion models that can operate at the city scale, carbon emissions in urban area can be estimated by inversion method. NIST researches are summarized and future works in this field by NIM of China are in plan.

According to the definition of contrast and contrast sensitivity function, a method of producing test targets for human eye contrast sensitivity measurement is proposed with integrating spheres and special light modulators. Then an automated measurement system is built and human eye contrast sensitivity function can be measured by psychophysical experiment with cross ladder method. Its spatial frequency covers 0.8, 1.5, 2.0, 3.0, 4.5, 6.0, 12.0 and 18.0 cycles per degree of visual angle. The indication error of background luminance of test targets satisfies ±5%, and contrast repeatability is 0.001 and reproducibility is 0.004, which meet requirements of human eye contrast sensitivity measurement.

With the new spectral irradiance measurement facility based on blackbody BB3500M of NIM (National Institute of Metrology), a bilateral spectral irradiance comparison was carried out between NIM and VNIIOFI (All Russian Research Institute for Optical and Physical Measurements) in the spectral wavelength from 250 nm to 2500 nm in the period from December 2014 to January 2015. The temperature measurement of the high temperature blackbodies were traced to the Pt-C and Re-C fixed point blackbodies and checked against the WC-C fixed-point blackbody for the two institutes respectively. The consistency of the temperature at 3021K is better than 70mK. The comparison result shows that the average relative deviation of spectral irradiance at the 44 wavelengths is 0.45%. The consistency is better than 0.9% except the maximum deviation 1.1% at the wavelength of 2000nm. The spectral irradiance units measured by NIM and VNIIOFI in this comparison are in agreement within the combined standard uncertainties of the laboratories over the wavelength range compared.

The principle and methods of optical radiation measurement was illustrated. The absolute spectral responsivity of Si trap detectors and InGaAs trap detectors were calibrated with the absolute cryogenic radiometer at eleven wavelengths between 400 nm and 1700 nm, which are 476.1, 488, 514.7, 521, 568, 632.8, 647.1, 785, 852, 980, 1064 and 1550 nm, respectively, with measurement uncertainties better than 0.05%. The absolute spectral responsivity curves of Si trap detectors were calculated by quantum efficiency model. The absolute responsivity of three wavelengths was applied to get absolute spectral responsivity from the relative spectral responsivity of InGaAs detector. Results show that the two types of trap detectors can be used to calibrate and transfer optical radiation value in the visible and near infrared spectral range.

According to the Non-orthogonal total station system principle, the main sources of the system measurement error are the rotation angle errors of rotary tables and the distance measurement error of the laser range finder. Using GUM algorithm, the uncertainties of these two sources are estimated and the system measurement uncertainty is evaluated. The result is validated by the simulation on MATLAB and the experiment conducted in the laboratory. The results show that when the distance is constant, the measurement uncertainty is almost independent of the horizontal angle, and increases with the absolute value of the vertical angle. When the angle value is constant, the measurement uncertainty increases with the distance from the measured point and the calibration point on the collimated axis.The accuracy of the simulation results is preliminarily verified by experiments.

Through analysis on the characteristic of twisted high birefringence fiber grating, a novel torsion sensor which can be embeded in the engineering material is proposed. Based on the coupled mode theory and thecharacteristic of twisted high birefringence fiber, the mathematical model of twisted high birefringence fiber grating transmission light is established and the spectral characteristics is analyzed, the simulation results show that the reflective spectra of twisted high birefringence fiber grating does not have the direction, and is only related to the torsion angle size.When the twist angle changes from 0 to 360°, the two peak wavelength of high birefringence fiber grating are resulting in drift, light of x direction moved to the short wavelength direction, light of y direction moved towards long wavelength, and the reflection spectrum peak decreases gradually, through combining the prior to the coupled mode theory with the reverse coupled mode theory, analyzing and simulating,the conclusion that x and y directions wave peak variation are drew, and the center wavelength changes corresponding amount, finally make a validated through experimental data of the relationship between changes of parameters of high birefringence fiber grating and torsional angle.

The high pressure pVTt gas flow standard facility in National Institute of Metrology(China), the expanded uncertainty of the facility could be 0.06% (k=2), while the expanded uncertainty of discharge coefficient of calibrated sonic nozzle is 0.08% (k=2). The measurement capability of the new pVTt facility was verified with the comparisons among the existed pVTt facility and the gas flow facilities in Physikalisch-Technische Bundesanstalt(Germany) with 3 sonic nozzles as transfer meters.The comparison results show in good agreement with each other of devices.

Aiming at mode mixing of empirical mode decomposition (EMD) caused by the intermittency signal, a new method to eliminate mode mixing of EMD based on analytical mode decomposition, AMD, is proposed. In this method, taking advantage of instantaneous frequency characteristics of the first intrinsic mode function, IMF, the frequency components of IMF1 can be got, the bisecting frequency and the location of the intermittency signal. Then, AMD is used to extract the intermittency signal and decompose the processed signal by EMD method. Thus, the effect of the intermittency signal is eliminated. The results of simulation analysis and engineering application show that the proposed method can effectively eliminate mode mixing of EMD caused by intermittency signal.

For the influence of load variation on its torsional vibration, the application range of single-phase induction motor is limited. In order to analyze the effect mechanism of load variation on torsional vibration, the mathematical models of single-phase induction motor are established firstly, including the simplified equivalent circuit and corresponding phasor diagram, meanwhile the ellipse degree of rotating magnetic field is defined. Then the load is changed under the motor rated voltage, the torsional vibration of motor is tested and the results show that the existence of minimum, and the parameters of motor winding are changed correspondingly. The experimental results are analyzed by using phasor diagram finally, and the effect mechanism of load variation on torsional vibration for motor is revealed.

Based on the measurement of sound absorption coefficient in reverberation room, the source of the uncertainty of measurement result is identified. Uncertainty components are further analyzed, results showed that the measurement uncertainty of absorption coefficient is mainly introduced by measurement of reverberation time, the volume of reverberation room, size of specimen and velocity of sound measurement have little contribution to the uncertainty of sound absorption coefficient measurement. The uncertainty of reverberation time measurement depends on the diffusion degree of room sound field , the contribution of measuring device is small.

The overall quantization error (EOQ) of CORDIC algorithm is discussed based on grating digital subdivision technique. Simulations and circuit experiments are conducted according to the basic principles of CORDIC. The result shows that the difference between predicted and experimental values is inversely proportional to the number of iteration (n) under the conditions of different binary width (b). The difference between the two reaches 1.8×10^-4rad, when n is equal to 12. It proves the effectiveness of the usage of EOQ to value the error of the algorithm in the calculation of angle. A quantitative analysis on error components and key parameters which influence the EOQ is presented. The result shows that the trend of EOQ becomes smaller with the increase of n and b, in which n plays a decisive role in the reduction of EOQ. Circuit test result shows that when the b remains unchanged, EOQ probably decreases by 50% with n adding once. The paper concludes the impact on the angle calculation based on CORDIC caused by EOQ. The conclusion has important significance and practical value to the error analysis in the process of digital subdividing for grating.

The system with 7 153.748^-7-154.354 cm^-1 line-pair based on tunable diode laser absorption spectroscopy (TDLAS) is designed for temperature measurement of premixed flat flame. Due to the weak absorptions, the signal-to-noise ratios (SNR) are low, and the relative deviation between TDLAS and thermocouple are larger. Therefore, the dual lasers TDLAS system with (7 185.597-(7 444.352+7 444.371) ) cm-1 line-pair, which is combined long path method, is developed for improvement of measurement accuracy. The result shows that the selected range will be broaden by using dual lasers, and the stronger line pair will be selected for improvement of SNR. Furthermore, combined the long path method, the relative deviation between TDLAS and thermocouple can be reduced from 10% to 5%.

Aiming at a 1220 strip surface, where the cold rolling mill had chatter marks, on which the reasons for the formation was tracked tested for in-depth study.Based on the vibration test, the analysis was given to the dynamic characteristics of the rack and the various phases of work rolls in the cycle on vibration signal.It was found that in its middle or late phase of the backup roll being used, the mill mainly worked with the 7th-order natural vibration at app.600Hz. When the rolling speed was maintained in the stable middle-/high-speed rolling phase, the relative movement of the work roll to the intermediate roll caused the formation of the chatter marks in the work roll surface.This had reaction to the mill that caused the forced vibration mill to further accelerate the formation of chatter marks, where mill vibration came along with both the resonance and forced vibration.In the analysis of the mechanism on the chatter marks, the relationship between chatter marks spacing and vibration source was considered in successfully finding out the cause of the 1220 mill chatter marks generated, and then the chatter marks suppression measures were proposed with satisfied effects.

Three methods were used to calibrate the tip area function of the nanoindenter at super low indentation depth, they are direct method based on atomic force microscope (AFM), spherical surface fitting method and indirect method based on the measurement results of the reference block of fused silica. It was revealed that tip area function calibrated by the direct method is mostly reliable and precise, of which the geometry morphology of the top end of the nanoindenter tip was truly fitted. Moreover, the corresponding mathematical model was established to analysis the main error of the AFM method, which was the error caused by the curvature radius of the AFM tip. The results show, under the super low indentation depth, the relative error of the tip area function of the nanoindentation is increasing with the decrease of indentation depth, which is mainly due to the curvature radius of the AFM tip. The result of the study is meaningful to the nanoindentation measurement of the thin films, of which super low indentation depth is usually required.

S11 phase metrology methods is based on theoretical derivation of the transmission line theory.  In experiment, the open kit, short kit, air lines and other standard devices are used to verify the correctness of the theory program.  In the experiment, the error distribution law is also found.  A mechanism model of errors is proposed, and numerical simulation verifies the rationality of the model.

The RTU and RBC were used to calibrate and evaluate the F900 high precision thermometry bridge in the middle temperature primary standard laboratory of the National Institute of Metrology, and the effect of different frequency and output current on its measurement accuracy was analyzed in the temperature range of long-stem standard platinum resistance thermometer. The results show that the accuracy is obvious difference when the bridge works in different frequency. When the frequency is 25Hz, the maximum measurement deviations in the calibration of RTU and RBC are about 0.01mK and 0.06 mK. When the frequency is 75 Hz, the maximum measurement deviations of the calibration are about 0.08mK and 0.2mK, and it has made significant drift compared to that of the factory. Differences in accuracy is very small when the bridge works at different output current, less than 15μK. The results using RTU and RBC to calibrate F900 can confirm each other, and provide data to the uncertainty evaluation in reproduction process of the fixed-point temperature reference.

Landweber iterative algorithm with updated sensitivity matrix is studied to improve the quality of reconstructed images. The initial image for sensitivity matrix update was obtained by Landweber iterative algorithm, and the results of different sensitivity matrix update intervals are compared. The times of sensitivity matrix updating are also analyzed. Experimental and simulation results showed that reconstructed images with higher accuracy can be obtained.

The direct luminance method is used to measure the coefficient of retroreflected luminance. The test system is build and the experiment is carried out with the retroreflected marks as the test object.The test and comparison of the direct luminance method and direct luminous intensity method is conducted.The experiment results show that the direct luminance method has obvious advantages on the aspects of the stray light requirement of the darkroom, the measurement object, the measurement distance, and the measurement accuracy. At the same time the direct luminance method has the advantages that the measurement process is simple and the measurement uncertainty reach 3.27%(k=1.96).

A high precision vacuum blackbody（H500 type）with the temperature range between -93 ℃ to 220 ℃ is developed at the National Institute Metrology of China. The performances are tested under the vacuum and low background condition (liquid-nitrogen-cooled shroud). The major technical parameters of the blackbody, such as the emissivity and uniformity are measured at room temperature and atmospheric environment. When the heating rate is 1 ℃/min, the time is shorter than 50 minutes and the temperature stability is better than 0.01 ℃ during 10 minutes. The emissivity of the blackbody at 20 ℃, 30 ℃ and 50 ℃ are 0.996 5, 0.9966 and 0.996 3, respectively. The temperature uniformity at the bottom of the blackbody cavity is better than 0.03 ℃. The expanded uncertainty is better than 0.1 ℃（k=2） over the entire temperature range.

The coefficient of thermal expansion of copper of face centered cubic crystal varying with temperature are investigated, and precision instruments DIL402PC thermal expansion instrument measured thermal expansion coefficient of copper in the experiment,that the expansion coefficient of the copper remained in the 2.0836×10^-5/℃ between 100℃and 380℃ is founded,which is larger than that of the general measurement of instruments in the laboratory. When it is over 380℃, coefficient of thermal expansion of copper increases linearly with temperature. The results of theoretical analysis and experimental determination remain basically consistent, which results show that the application of this theory can also explain the coefficient of thermal expansion of face-centered structure of other crystal.

Aiming at the logic entanglement between systematic error and precision, and analyzing the most typical systematic error in geodesy field, this article reveals the errors classification theory actually comes from the narrow perspective caused by measurement specialization and that it is a narrow philosophical view such as the India philosophy story “six blind men and an elephant”. Through proving that systematic errors also follow random distribution and discussing some related problems, this article has proposed a new error epistemology that all errors follow random distribution, and confirmed that only the measurement uncertainty concepts system is scientific, and given the reasons that the definition of errors classification and some conceptions-derived, such as of precision, trueness and accuracy, should be erased.

A self-sensing atomic force microscope (AFM) measuring head is developed based on a commercial quartz turning fork probe. The measuring head is easy to integrate and it can detect the amplitude variations of the cantilever through the electrical signal instead of using optical detection components. A weak signal detection and parasitic capacitance compensation circuit is designed for the measuring head. The amplitude signal of the measuring head is obtained using a commercial lock-in amplifier. And on this base the force-distance curve and resolution of the measuring head in amplitude modulation mode is tested. Using the PID module in lock-in amplifier, the topography of the sample is measured in amplitude modulation mode. The results indicated that the sensitivity of the measuring head is 0.624 mV/nm, and the resolution of the measuring head can reach less than 2 nm.

The primary heat capacity standard for medium temperature is employed for the traceability of the specific heat capacity, phase transition temperature and enthalpy. The device mainly adopts the adiabatic calorimetric method, which makes the calorific value traceable to SI units. Firstly, the research significance and the principle of primary heat capacity standard is introduced, and then the progress on the research in the field is demonstrated. Finally new design and scheme of primary heat capacity standard based on this work are put forward.

Utilized the property that kernel function learning can solve efficiently the linearly inseparable problem of image features, and combined advantages of sparse representation algorithm, a novel image feature extraction method is proposed. Here the sparse representation of images is realized by the winner-take-all rule based independent component analysis method, which can extract image high-dimension features efficiently and has quicker convergent speed, because it is unnecessary to optimize high-order nonlinear function and estimate sparse density. Compared with the winner-take-all rule based independent component analysis method, the experiment results in PolyU database testify that image features extracted by the combination method of kernel function learning and sparse representation can favor to improve the precision of feature classification.

Gradient method, surface fitting and N-R method are 3 main sub-pixel displacement algorithms of digital speckle correlation method to improve the precision of the measuring system. The principles of three kinds of algorithm were studied and numerical simulation was carried out. To compare the different precision from 3 methods under noise, the computer models generate a series of speckle gram whose displacement is 0.01 pixels and different Gaussian noise was added in generated graphics.  The results showed that in the precision requirement in 0.01 pixels, the upper bounds on noise variance of gradient method and N-R method are respectively 0.006 and 0.000 5, and the calculation precision of surface fitting method has huge uncertainty, gradient method is more suitable for engineering application.

Deal with the limitations of measurement uncertainty evaluation method based on ISO GUM, A new approach to the evaluation of measurement uncertainty based on the polynomial chaos theory is presented. The main assumptions behind the measurement uncertainty propagation based on the GUM is analyzed. The measurement uncertainty evaluation used the PCT approach is provided. By the GUM and PCT method, the relative absolute difference between the confidence obtained in the two cases and the true value is computed. It is show that in case of a distribution very different from the Gaussian, the polynomial approach leads to results very close to the ideal case.

A novel calculation method based on parabola curve-fitting is presented for peak calculation. Through taking out the waveform near impulse peak from acquisition data, the impulse peak value is got by using parabola curve-fitting. The method has the specialties of easy to use, good convergence, and so on. By the error of curve-fitting,  the different curve-fitting results can be compared. In this method, the sampling data are used to calculate the impulse peak directly, so, there is no affects and influence of filters, and it can attain the more precise and  impersonal peak results. In a group of impulse calibration experiments, and through compared with traditional method, both the correctness and the feasibility of the pulse peak calculation method are proved.

GUM Sup.1 is concerned with the propagation of distribution through a mathematical model of measurement as a basis for evaluation of uncertainty of measurement. It introduced the principles and the detail processes of Adaptive Monte Carlo method to carry out the propagation of distribution. Then two measurement models were provided, including linear model and non-linear model, to validate the applicative of Adaptive Monte Carlo method. And it proved that both models reached the reasonable evaluation results. At the same time, some problems such as how to choose proper Monte Carlo simulation sample M and numerical tolerance δ were still need to be further researched.

In order to establish a reliable thickness-measuring fitting model for approximate 1 nm thickness HfO₂ film using spectroscopic ellipsometry, the thickness of a ultrathin HfO₂ film was measured by a grazing incidence X-ray reflection diffractometer, which belongs to a part of country / region interlaboratory comparison and it used as the reference value of ellipsometry model thickness. It investigated the selected dispersion model and fitting parameters of HfO₂ film. The results show that the optimized fitting conditions are obtained, and Tauc-Lorentz 3 for the dispersion model is selected with wavelength ranging from 3.45 eV to 4.35 eV and the ratio of the HfO2 to porosity equals 60:40.

In order to align two probes of dual-probe atomic force microscope (AFM), it is necessary to establish a measuring head to do in-depth research on the probe A scanning the probe B. Firstly, the mechanical characteristics of the probe are obtained by finite element (FE) simulations. Secondly, using the locked-in amplifier to attain the amplitude and frequency signals to analyze the system resolution (better than 1nm), the probe is rotated 90 degrees compared traditional AFM. Lastly, probe B is scanned by probe A in YOZ plane, reducing the scanning range and scanning step gradually. The alignment accuracy is of 5 nm.

A method for data analysis for thermal conductivity measurement using transient hot-wire method is present. Numerical simulation is introduced in data processing. Finite volume method is used to solve the control equations. The finial result is obtained by comparison of the simulated temperature curve with the experimental temperature curve. The presented method is very effective for experimental data analysis. The correct result could be gotten with much less data points, which is very helpful for the design of experimental system.

By means of high-temperature reduction method, the oxidized mercury will be reduced to elemental mercury without any catalyst, which is convenient for the monitoring of mercury in flue gas. Using differential optical absorption spectroscopy (DOAS) to inversion the concentrations of mercury, and then comparing that with the outcome resulted from experiment without the high-temperature device to verify the applicability of high temperature equipment, and to carry out experiments mixed with different concentrations of the elemental mercury and mercury oxidation. By probing into the impact of genetic algorithm, FFT and the integral area method on the concentration of mercury in flue gas based on the traditional DOAS algorithm, it’s turned out that the traditional algorithm is of contingency with a comparatively large overall error, while the Fourier transform inversion error is too large, the algorithm of integral area inversion has a lower error and a stable volatility than genetic algorithm and integral area inversion error minimum of 0.55%. The volatility of genetic algorithm is also not as stable as that of integral area inversion, which demonstrates that the integral area inversion is the most applicable for the inversion of low concentration of mercury.

With a brief introduction of optical theory of photogrammetry, the relation of the location of datum marks is described in camera lens system between air and underwater. The collinearity theory of underwater photogrammetry is proposed, and the variety of principal distance of underwater camera is illustrated.After the analysis of distortion and view of underwater photography, the camera underwater calibration method is described.One calibration test on underwater camera was done.The results indicate that the collinearity theory of underwater photogrammetry is right and the method of underwater camera calibration is suitable.

Basic principles of ultra-stable lasers and Pound-Drever-Hall（PDH）method are introduced. Additionally, methods of reducing noises, such as noises from vibration, temperature perturbation, air turbulence and etc. are discussed. The applications of ultra-stable lasers, especially the application of ultra-stable lasers to achieve the ultra-stable microwave source are described. Finally, an ultra-stable laser system with parameters for an ultra-stable microwave source is presented.

Based on the principle of ultrasonic resonance spectrum, a setup is developed including the ultrasonic signaling and detecting system, the thermostat and the data analysis software.The elastic modulus of three samples in different quality factors are measured at room temperature, and the effects influencing the measurement are investigated. The resonant frequency matching error (RMS) of 0.04% has been reached with the measurements by the developed setup. The results agree well with those of the global advanced commercial instruments. In addition, bearing steel（9Cr18）are measured at temperature from 293 K to 353 K for isothermal compressibility. The system is capable to measure the elastic modulus of solids at temperature up to 500 K at anti-oxidation atmosphere. After redesigning the ultrasonic signaling and detection system, it is capable for measurements at higher temperature.